1. Field of the Invention
The present invention relates to a carbon nanotube film structure and a method for fabricating the same.
2. Discussion of Related Art
Carbon nanotubes (CNTs) produced by means of arc discharge between graphite rods were first discovered and reported in an article by Sumio Iijima, entitled “Helical Microtubules of Graphitic Carbon” (Nature, Vol. 354, Nov. 7, 1991, pp. 56-58). CNTs are electrically conductive along their length, chemically stable, and each can have a very small diameter (much less than 100 nanometers) and large aspect ratios (length/diameter). Due to these and other properties, it has been suggested that CNTs can play an important role in many fields, such as microscopic electronics, field emission devices, thermal interface materials, etc.
However, the main obstacle to an actual application of carbon nanotube use is their difficulty to process, due to the powder form of the carbon nanotube products. Therefore, carbon nanotubes are formed into films to facilitate handling and processing thereof.
At present, different methods are widely used for fabricating carbon nanotube films including: a growing method, a spraying method, and a Langmuir-Blodgett (LB) method.
Through the growing method, a carbon nanotube film is grown on a chemically functionalized substrate directly by adopting multiple catalyst layers. However, the method typically requires high temperature during growing process and cannot be applied to such a substrate made of plastic.
Through the spraying method, carbon nanotubes, dispersed in a solvent, are sprayed on a substrate. In this method, however, carbon nanotubes cannot be well-dispersed, due to an aggregation thereof, and thus, a uniform film cannot be formed.
Through the Langmuir-Blodgett (LB) method, carbon nanotubes are soluble through an introduction of amide groups therein, and then through a step of “molecular self-assembly”, the film accumulates on a substrate. However, the method has such a problem that carbon nanotubes are disordered in the film.
What is needed, therefore, is to provide a carbon nanotube film structure and a method for fabricating the same, in which the above problems are eliminated or at least alleviated.